Calibration methods are generally known in conjunction with computer tomographic systems (CT systems). With these known calibration methods however detectors are calibrated in measurement ranges which do not fall into the saturation range of the detector but in ranges in which a linear behavior between radiation intensity striking the detector and a signal response is largely used as the basis. Quanta-counting detectors lie in the range of the radiation intensity used for X-ray diagnostics in CT examinations at least partly in the range of strong non-linearity however, with paralysis phenomena already occurring in the detector here.